1. Field of the Invention
The present invention relates to an accelerator, an information processing apparatus and an information processing method, and more particularly, to an accelerator having multiple calculation units which can connect to an information processing apparatus and execute a program by processing the program in parallel, the information processing apparatus connected to the accelerator, and an information processing method.
2. Description of the Related Art
Conventionally, there has been known a technique configured to attach a device having a calculation function to an information processing apparatus and cause the attached device to share a part of a process to be executed. For example, there is a technique in which the device having the calculation function, which is called “accelerator”, is mounted in a personal computer (hereinafter referred to as “PC”) as the information processing apparatus and a Central Processing Unit (hereinafter referred to as “CPU”) in a body of the PC causes the accelerator to share the process of a program, with an intention of improving a processing speed.
Recently, an information processing apparatus having the accelerator attached to its body unit, not only with an intention of sharing the process or improving the processing speed, but also in consideration of power consumption, has also been proposed, for example, in Japanese Patent Laid-Open No. 2003-15785.
According to a technique according to the proposition, the CPU at the body unit side reads performance information on the attached accelerator, and based on the performance information, determines and sets a driving voltage or a driving frequency for the accelerator, which enables the accelerator to be driven correspondingly to a low power consumption mode and the like.
However, in the case of the information processing apparatus according to the above described proposition, since the CPU at the body unit side determines the driving voltage and the like for the accelerator, the CPU has to execute a determination process thereof, causing an overhead in the CPU.
Moreover, the information processing apparatus according to the above described proposition has not considered such a case where there are multiple calculation units within the accelerator.